Firearm



0. HORSRUD Feb. 9, 1943.

FIREARM Filed Aug. '7, 1939 2 Sheets-Sheet 1 0. HORSRUD Feb. 143.

FIREARM Filed Aug '7, 1939 2 Sheets-Sheet 2 Patented Feb. 9, 1943 FIREARM Ole Horsrud, Fox River Grove, 111., assignor to Sears, Roebuck and (30., Chicago, 111., a corporation of New York Application August '7, 1939, Serial No. 288,793

3 Claims.

This invention relates to firearms and is concerned more particularly with firing mechanism therefor.

Past firearm constructions have been more or less unsatisfactory because of excessive wear between certain parts of the control mechanism, resulting in impairment of accuracy and efficiency early in the life of the firearm. To overcome this defect and provide a firearm construction of enhanced reliability and of practically indefinite life is accordingly the essential object of my invention.

Another object is to provide a fire control mechanism in which substantially all of the wear occurs at places not vital to the accuracy and efficiency of the firing mechanism.

A further object is to provide a fire control mechanism in which wear at places vital to the efficiency of the mechanism is negligible.

It is a further object of the invention to provide an improved positive locking mechanism for a firearm.

It is another object to provide a firing mechanism such that a major part of the strain when the mechanism is cocked is taken by a relatively stationary member or members.

Another object is to provide a sear and striker assembly formed to minimize strain on the sear and sear control mechanism.

It is a further object to provide a firing mechanism in which friction between the sear and the striker is practically non-existent.

It is also an object to provide an improved adjustment for the trigger pressure.

A further object is to enable the sear to pass substantially instantaneously from fully obstructing position to fully unobstructing position.

Another object is to provide a striker and bolt construction affording minimum friction therebetween.

It is another object to enable the striker to be in full flight from its rearmost position.

Further objects and advantages of the invention will appear as the description proceeds.

The invention will be better understood upon reference to the foregoing description and the accompanying drawings, in which:

Fig. 1 is a fragmentary longitudinal sectional view of a firing mechanism embodying features of the invention, with the striker cocked.

Fig. 2 is a fragmentary elevation of a portion of the structure appearing in Fig. 1, but taken from the opposite side.

Fig. 3 is a view similar to Fig. 2 but with a portion removed to disclose certain details.

Fig. 4 is an enlarged sectional View taken substantially as indicated by the line 4-4 in Fig. 1.

Fig. 5 is a view similar to Fig. 1 but with the parts in the relations assumed when the striker fires the bullet.

Fig. 6 is similar to Fig. 1 but shows a modified firearm construction.

Fig. '7 is similar to Fig. 5 but shows the modified form.

Fig. 8 is a sectional view taken as indicated by the line 88 in Fig. 6.

Figs. 9 and 10 are fragmentary elevations showing the firearm unlocked and locked.

Referring now more particularly to the drawings, wherein the same reference characters dosignate the same parts, a receiver ill is shown adjacent a barrel ll adapted to receive a bullet 12 in a shell It. The receiver carries a bolt I5 provided with the usual handle [6 by which the bolt is adapted to be turned and translated in the bore I! of the receiver.

The bolt comprises a forward section I9 having an elongated narrow recess housing a striker or hammer 2| adapted for limited longitudinal movement in said recess, said striker having a firing pin 22 which at all times is disposed in a hole 24 which renders the cap or primer 25 of the shell accessible to the pin. The striker 2| is of generally flat cross section conforming to the recess 20 and has a slot 21 for the accommodation of thrust bearings 28 and 29 between and about which a firing spring 3| is disposed, the sides of the recess 20 being enlarged as at 32 in Figs. 4 and 8 to accommodate said bearings and spring. A pin 33 mounted on the bolt I9 serves as a reaction member limiting the bearing 29 rearwardly. The rear end of the slot 26 provides shoulders 35 engageable with the bearing 29 and a recess 36 providing clearance for the pin 33 and having a wall engageable with the latter, thereby to limit the firing forward stroke of the striker.

In the form shown in Figs. 1 to 5, the bolt [5 has a rear peripheral shoulder 40 and an extension ll of reduced diameter, said extension being diametrically slotted as at 42 in continuation of the recess 20 in the bolt. Rotatably and slidably fitted about the reduced extension 4! is a collar as to which the handle I6 is secured. The collar #35 may comprise rigidly connected outer and inner sleeves and is preferably slidably engageable with the shoulder 40. A retainer plug 39 releasably threaded at 50 within the rear end of the reduced portion 4| of the bolt is limited by said portion so that the collar 45 has sliding engagement with the shoulder '53 on the plug, when the plug is threaded home. A friction spring ring 54 may be provided to take up play.

The collar 35 may have diametrically opposed slots 56 from which extend helical cam slots 51 as shown in Figs. 1 and 5. The striker 2! has a reduced rear extension or neck 59 projecting rearwardly into the reduced bolt portion ll and disposed in the diametrical slot 42 thereof, and terminates rearwardly in cam follower lugs 6! adapted to project into the slots 51 of the collar 35. When the striker has fired and is thus in its foremost position, as shown in Fig. 5, the lugs El are disposed at the forward ends of the associated cam slots 57 and are so arranged that rotation of the collar 35 in the proper direction will cause the forward walls of the cam slots to force the firing pin 2| rearward against the action of the spring 3i. When the handle it is pulled and swung from its down position (Fig. 5) to its uppermost position, it retates the collar $5 to effect a rearward camming of the striker 2!.

The receiver [El may have a suitable catch (not shown) cooperating with the bolt l5 to prevent rotation of the forward section l9 thereof while permitting the bolt to move axially in the bore I1.

The receiver ID has a longitudinal channel or keyway 65 adapted. to receive a scar 66 pivoted at its forward end as shown at 67 to the forward section E9 of the bolt. The scar extends rearwardly from the pivot 67 and has an inclined rearwardly facing abutment or shoulder 'IEI engageable with a forwardly facing abutment or shoulder ii on the striker 2 I. These shoulders are adapted to be interengaged when the striker is in its rearmost or cocked position. At such time, the shoulder ii] on the sear 66 is adapted to obstruct the forward movement of the striker 2| and thereby prevent firing. The inclination of the surfaces '16 and H is such that, at the moment the sear is released, as will appear, the spring 3! will exert a force which, acting through the shoulder H on the striker, will cam the sear downward out of obstructing position and will cause the striker to fire. The inclination of said shoulders, moreover, is such that, while the sear is supported in obstructing position, substantially less than the full force of the spring 3! is communicated to the sear pivot pin 61, so that said pin is subjected to minimum stress consistent with correct design of the sear supporting mechanism, as will appear.

For controlling the position of the sear 66, I provide a bell crank lever dog pivoted as at 16 on side plates of a bracket 7'! or other suitable means mounted preferably on the receiver ID as at it and elsewhere. The dog 15 has an upwardly extending arm 80 engageable with the bottom side 8| of the sear 68 when the shoulders 'H] and H are interengaged, and is adapted to be rigidly held there by a latch 83 engaged in the recess 8 5 in the other arm 85 of the lever. The latch 83 is formed on a trigger 81 pivotally mounted as at 88 on 3. depending extension 89 on the bracket 11, and is urged upward by spring means SH. With the parts thus arranged, it is evident that firing of the striker pin 2| is positively prevented.

The bracket 1! may be U-shaped, providing a bight 95 disposed rearwardly of the dog 15 and having a bearing opening 95 through which a pin 91 pivotally connected as at 98 to the arm 85 of the dog 15 is slidably extended. A spring I60 disposed about the pin 9! and engaged with a shoulder it! on the pin and with the bight 95 urges the dog to swing clockwise as seen in Figs. 1 and 5, so as to urge the dog arm 30 toward the bottom surface 6| of the sear 66. Compared to the spring 3|, the pressure of the Spring Hi0 is very light, so that it olfers negligible resistance to the action of the spring iii in thrusting the sear 66 downward when the latch 83 is released.

When the dog '55 is in locked position, as shown in Fig. 1, its contact point N33 is so disposed as to turn about the pivot 15 in response to the downward thrust resulting from the pressure of the spring 3i when the latch 83 is out of the recess 84.

Fig. 5 shows the relation of the parts when the firearm has been fired. To cock the firearm, the handle it is turned through a suitable angle in the receiver iii, say about 90", thereby turning the collar 45 and the forward walls of the cam slots 57 to engage the lugs 6| and cam the striker rearwardly against the resistance of the spring 3!. The forward ends of the lugs may be rounded as at 82 to minimize friction. The spring 9! at this time is pressing the latch 83 upward, and the spring Hit] is urging the bell crank lever arm 86 toward the sear 66 and thus pressing the sear upward into engagement with the striker adjacent the shoulder 74 thereof. As the upward rotation of the handle l6 moves the striker rearward, the spring liifi moves the sear E5 upward to effect engagement between the shoulders iii and ii, the arm of the dog 15 also moving to bring the recess 84 thereof closer to the end of the latch 83. When the striker is fully withdrawn by the cam action, the spring it causes the shoulders Hi and H to be fully interengaged and the contact end H13 of the dog F5 to engage the bottom 8| of the sear 66, and enables the spring 9| to slip the latch 33 into the recess 34, all as shown in Fig. 1. At such time, with the handle [6 in its upper position, the forward walls of the cam slots 51 are engaged with the lugs 6| so as to permit the proper positioning of the scar and control mechanism therefor as just described. Now when the handle I6 is depressed, the sear being locked by the dog 75 and trigger 8'! in the position shown in Fig. 1, positively prevents the striker from moving forward. The downward movement of the handle it is limited by an abutment (not shown) in the receiver ii], and when the handle is brought to rest in its down position, the lugs iil are alined with the slots 56 in the collar 55, so that the forward walls of the cam slots 5'! offer no obstruction to the firing stroke of the firing pin. Now the firearm is fully cocked, and, to fire the same, it is necessary merely to pull the trigger 8'1.

The rear part of the keyway 65 is formed to accommodate the sear 66 so that the entire bolt may be removed if desired.

It will be observed that the line of action of the force on the dog E5 in response to the pressure of the spring 3i is adjacent the axis of the pivot pin Hi, so that the component in that direction of the force of the shoulder H on the shoulder H3 is resisted very largely by the pin 16 and the bracket TI and accordingly by the receiver i0. Only a relatively small part of the force is taken by the latch 83 and transmitted thereby to the trigger pivot pin 88. In the movement of the trigger, there is friction between the latch 83 and the dog 75, and this friction, being relatively light, will not cause appreciable wear of the surfaces involved. Also, by virtue of the fact that the latch 83 is subjected to a relatively light force, the trigger pivot pin 88 likewise is subjected to negligible wear. Moreover, even if excessive wear of the frictionally engaged surfaces of the dog 15 and latch 83 or of the trigger pivot pin 88 could take place, the sear 58 could be depressed to only a negligible extent by the spring 3I during the movement of the latch 83 to a position clear of the dog 15, so that the resulting wear on the surfaces 18 and II would be negligible. It is thus apparent that the operation of the trigger results in substantially no wear to the surfaces affecting the proper operation of the striker. When the trigger is pulled clear of the dog 15, the passage of the shoulder 1I over the shoulder 18 is practically instantaneous, the sear 86 offering substantially no resistance to such movement. Consequently, the friction between the surfaces 18 and H is practically nonexistent and, as a result, the surfaces will remain in their original condition indefinitely, thus insuring the same accurate firing process throughout the life of the firearm.

The trigger has a bearing surface IIII extending rearwardly and below the bight 95, and has a recess III receiving the lower end of a spring II2. Received in the upper end of the spring is a projection II I formed on the bracket bight 95. A screw II1 carried by the trigger is adapted to engage the spring I I2 and to adjust the pressure thereof. The spring H2 is relatively light, compared to the spring SI, and accordingly, adjustment of the screw III will effect slight changes in the spring pressure on the trigger.

The bracket 11 may be fastened at the rear thereof to the receiver III in any suitable manner, as by a screw I28, and preferably has a slot IZI through which a keeper or latch I22, formed on a safety locking member I23, projects. When the firearm is cooked, as shown in Fig. 1, the lock member may be in inoperative position, as shown in Fig. 1, or it may be slid into operative position as shown by the dotted lines in Fig. 1. In this position, the keeper is substantially engaged with the bottom side 8| of the sear while the bottom I25 of the locking member is substantially engaged with a shoulder I28 on the trigger. Thus, the locking member positively locks both the sear and the trigger against releasing movement so that it is impossible for the striker 2I to fire.

The locking member I23 preferably has a side plate I38 slidably engaged with a face I3I on the receiver I8 and has a knurled or otherwise roughened thumb-engaging projection or handle I32 to facilitate movement of the locking member. The locking member I23 is preferably removably mounted as by screws I35 extending through a plate I38 and through slots I31 formed in the portion I38 of the locking member, said screws being threaded into the receiver I8. The screws and slots determine the limits of movement of the locking member. In one of the limits, the locking member is in inoperative position as shown in Figs. 1, 2 and 6 in full lines, and, in the other limit, the locking member is in operative position, as shown in dotted lines in Fig. 1. The projection I32 is preferably on the side at which the handle I8 is located, for greater convenience.

In the operation of rotating the handle I8 to cam the striker rearward, the forward walls of the cam slots 51 exert a rotative force on the striker in the direction of turning of the handle. With the arrangement illustrated in Fig. 1, the

upper left corner edge of the striker and the lower right corner edge of the striker, if sharp, might score the respective walls I48 and MI of the recess 28 and would themselves become worn, with the result that the proper firing of the firearm might be seriously aifected. The fit between the sides of the striker and the walls I48 and MI of the recess 28 is preferably such as to allow substantially no more than free sliding movement of the striker. Since such a fit requires some clearance, it is obvious that if the corner edges referred to were sharp, there may be a biting knife-edge-to-surface friction contact possibly resulting in the deleterious wear above referred to. To obviate such results, I have rounded said corner edges as shown at I43 and I44, in Fig. 4 thereby providing for engagement between a flat wall and a relatively blunt curved surface as shown, so that friction will be minimized. I

The sliding portion I38 0f the lock member I23 may be formed with openings or indentations I41 and I48, and the cover plate I38 with a spring depression or detent I48 adapted to snap in the recess I48 when the locking member I23 is in inoperative position and in the recess I41 when the locking member is in locked position.

In the form of the invention appearing in Figs. 6 to 10, the striker or hammer I68 has a neck IBI slidably fitted in the slot I52 in the reduced rear end I53 of the bolt I5. A sleeve I journaled on said end I63 is slidably engaged with the bolt shoulder 40 and a cap I86 is threaded in said end. The sleeve has a cam slot 51 cooperative With a lug I61 on the striker neck I 5| in the manner set forth above in connection with the lugs GI, so that when the ball handle I8 is raised the wall of said cam slot 51 in Fig. 6, retracts the striker against the resistance of the firing spring 3| to cocked position.

The sear I18 is pivoted to the receiver III at III and carries a spring I12 forward of the pivot, said spring bearing against the under side of the striker so as to at all times tend to turn the sear anti-clockwise. The rear end portion I13 of the sear has an inclined surface I14 complemental to an inclined surface I15 on the striker. A dog I16 pivoted at I11 to a bracket I18 mounted as at I19 on the receiver is constantly urged by a spring I88 to turn clockwise, an arm I8I of the dog being engageable with the rear end I13 of the sear to press the sear surface I14 against the striker surface I15.

A trigger I83 pivoted at I84 to the bracket I18 is urged clockwise by a spring I85 compressed between the trigger and an anchoring member I88 carried by the bracket and adjustable by hand or a suitable tool. Thus, the other end I81 of the trigger automatically snaps into engagement with the shoulder I88 of the dog I16, as shown in Figs. 6, 9 and 10, upon retraction of the striker as aforesaid.

The safety lock means of Figs. 6 to 10' differs from that previously described in that the slide I98 abuts the receiver I8 and not the sear I18. The mechanism is locked when the slide I98 engages the surface I9I of the trigger as shown in full lines in Figs. 6 and 10 and is unlocked when the slide is disposed rearwardly of said surface as shown in full lines in Figs. 7 and 9 and in dotted lines in Fig. 6.

It is evident from the foregoing that I have provided with a minimum of parts a construction which enables the firing spring 3| to exert its full force in driving the striker from its extreme rear position to its firing position without interference from the sear 66 or other'means, so that the firing pin has acquired maximum momentum possible upon its striking the shell cap 25. The parts are easily accessible, the stresses resulting from maintaining the striker in cocked position are taken largely by the gun frame so as to substantially relieve the trigger, and wear between the surfaces which might seriously affect the efiiciency of operation is negligible. A simple yet effective double acting lock is provided, and minute adjustments in the pres-- sure on the trigger are possible. The receiver ID may be provided with an opening (Figs. 1, 5, -6 and 7) through which a cartridge clip may be fed and used shells released.

The elements of the firing and fire control mechanism may be of steel or other metal or alloy of sufiicient hardness to withstand the conditions of use of the firearm, as is understood by those skilled in the art.

Various changes coming within the spirit of the invention may be suggested by those skilled in the art, and hence I do not wish to be limited to the specific forms shown or uses mentioned.

I claim:

1. In a mechanism for maintaining a firing pin in cocked position, a receiver, a bolt therein, a striker in said bolt and having a forwardly lacing shoulder, a scar mounted on said bolt and having a rearwardly facing shoulder eng-ageable with the aforesaid shoulder when the striker is in cocked position, a lever pivotally supported from said receiver and engaged with said sear, a trigger supported from said receiver and holding said lever in engagement with said sear, and a spring for firing said striker, said spring being inoperative while said trigger holds said lever engaged with said sear, said trigger being disengageable from said lever to render said firing spring operative, at least one of said shoulders being inclined upwardly and forwardly to enable said striker to cam said shoulders apart when said spring becomes operative.

2. A firearm comprising a bolt, a striker therein, a sear movable into and out of a position obstructing firing movement of said striker, said sear being movable by said striker out of obstruoting position, means pivotally mounting said sear on said bolt, said means being disposed in advance of the place of engagement, releasable means for maintaining said sear in obstructing position, said sear extending longitudinally between the place of engagement and its pivot, so that the forward component of the force of the spring is withstood by said bolt, the releasable means comprising a member engaging said sear opposite the place of interengagement between said striker and sear to preclude bending of said sear by said striker.

3. A firearm, comprising a receiver, a bolt therein, a striker in said bolt, a sear pivoted or. said bolt and movable into and out of a position obstructing firing movement of said striker, a spring for propelling said striker, said sear being movable by said striker out of obstructing position, means including a lever pivoted on said receiver for maintaining said sear in obstructing positon, the sear pivot being disposed to transmit the forward component of the force of the spring-pressed striker on said sear to said bolt, said lever engaging said sear at such a point that when the sear is swung out of obstructing position, it will swing the lever, and means releasably retaining said lever in position to maintain the sear in obstructing relation to the striker, the lever pivot being disposed to withstand a major portion of the downward component of said striker on said sear.

OLE I-IORSRUD. 

